{"id":34697,"date":"2025-05-05T13:12:03","date_gmt":"2025-05-05T13:12:03","guid":{"rendered":""},"modified":"2025-07-07T23:53:44","modified_gmt":"2025-07-08T05:53:44","slug":"cve-2025-4083-process-isolation-vulnerability-in-thunderbird-and-firefox-due-to-improper-handling-of-javascript-uris","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-4083-process-isolation-vulnerability-in-thunderbird-and-firefox-due-to-improper-handling-of-javascript-uris\/","title":{"rendered":"<strong>CVE-2025-4083: Process Isolation Vulnerability in Thunderbird and Firefox due to Improper Handling of Javascript URIs<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The vulnerability identified as CVE-2025-4083 is a severe process isolation flaw that affects popular web browser Firefox and email client Thunderbird. This vulnerability is due to the improper handling of javascript: URIs, which could potentially allow malicious content to execute in the top-level document&#8217;s process instead of the intended frame. This could enable a sandbox escape, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32857-sql-injection-vulnerability-in-telecontrol-server-basic-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"39755\">leading to potential system<\/a> compromise or data leakage. Given the widespread use of Firefox and Thunderbird, this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-4954-critical-file-upload-vulnerability-in-axle-demo-importer-wordpress-plugin\/\"  data-wpil-monitor-id=\"60728\">vulnerability is of high importance<\/a> and requires immediate attention and mitigation.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-4083<br \/>\nSeverity: Critical (CVSS: 9.1)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: Required<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-3928-unspecified-vulnerability-in-commvault-web-server-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"40375\">System compromise or data leakage due to potential<\/a> sandbox escape<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-2452911045\" class=\"ameeb-content-2 ameeb-entity-placement\"><div style=\"border-left: 4px solid #555; padding-left: 20px; margin: 48px 0; font-family: Roboto, sans-serif; color: #ffffff; line-height: 1.6; max-width: 700px;\">\r\n  <h2 style=\"margin-top: 0; font-size: 20px; font-weight: 600; display: flex; align-items: center;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"display: inline-flex; align-items: center; margin-right: 8px;\">\r\n      <img decoding=\"async\" src=\"https:\/\/www.ameeba.com\/blog\/wp-content\/uploads\/2025\/10\/Best-App-icon-Ameeba.png\" alt=\"Ameeba Chat Icon\" style=\"width: 40px; height: 40px;\" \/>\r\n    <\/a>\r\n    A new way to communicate\r\n  <\/h2>\r\n\r\n  <p style=\"margin-bottom: 12px;\">\r\n    Ameeba Chat is built on encrypted identity, not personal profiles.\r\n  <\/p>\r\n\r\n  <p style=\"margin-bottom: 16px;\">\r\n    Message, call, share files, and coordinate with identities kept separate.\r\n  <\/p>\r\n\r\n  <ul style=\"list-style: none; padding-left: 0; margin-bottom: 20px;\">\r\n    <li>\u2022 Encrypted identity<\/li>\r\n    <li>\u2022 Ameeba Chat authenticates access<\/li>\r\n    <li>\u2022 Aliases and categories<\/li>\r\n    <li>\u2022 End-to-end encrypted chat, calls, and files<\/li>\r\n    <li>\u2022 Secure notes for sensitive information<\/li>\r\n  <\/ul>\r\n\r\n  <p style=\"font-style: italic; font-weight: 600; margin-bottom: 24px;\">\r\n    Private communication, rethought.\r\n  <\/p>\r\n\r\n  <div style=\"display: flex; flex-wrap: wrap; gap: 12px;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\/download\" style=\"background-color: #ffffff; color: #000000; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Download Ameeba Chat<\/a>\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"border: 1px solid #ffffff; color: #ffffff; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Learn More<\/a>\r\n  <\/div>\r\n<\/div>\r\n<\/div>\n<p>Product | Affected Versions<\/p>\n<p>Firefox | Versions less than 138<br \/>\nFirefox ESR | Versions less than 128.10 and 115.23<br \/>\nThunderbird | Versions less than 138 and 128.10<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>This <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-27007-incorrect-privilege-assignment-vulnerability-in-brainstorm-force-suretriggers\/\"  data-wpil-monitor-id=\"42435\">vulnerability originates from the incorrect<\/a> handling of javascript: URIs by the affected browsers and email clients. An <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-28169-unencrypted-broadcasts-lead-to-potential-man-in-the-middle-attacks-on-byd-qin-plus-dm-i-dilink-os\/\"  data-wpil-monitor-id=\"40636\">attacker can exploit this flaw to potentially<\/a> run malicious content in the top-level document&#8217;s process instead of the intended frame. This could lead to a sandbox escape, which would essentially bypass the security measures in place and <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-22636-cross-site-scripting-vulnerability-in-vr-frases-leads-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"40170\">potentially compromise the system or lead<\/a> to data leakage.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-1875164865\" class=\"ameeb-content ameeb-entity-placement\"><div class=\"poptin-embedded\" data-id=\"f6b387694f681\"><\/div>\r\n\r\n\r\n\r\n\r\n\r\n<\/div>\n<p>Given the nature of this vulnerability, an <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2021-47663-unauthenticated-remote-attacker-gaining-full-access-due-to-improper-json-web-tokens-implementation\/\"  data-wpil-monitor-id=\"41605\">attacker might craft a malicious web<\/a> page with a script that exploits the flaw in handling javascript: URIs. While the below example is simplified and conceptual, it illustrates the type of attack that could be performed:<\/p>\n<pre><code class=\"\" data-line=\"\">GET \/malicious_page.html HTTP\/1.1\nHost: attacker.example.com\n&lt;html&gt;\n&lt;body&gt;\n&lt;iframe src=&quot;javascript:alert(&#039;This could be a malicious script executing in top-level document context&#039;)&quot;&gt;\n&lt;\/iframe&gt;\n&lt;\/body&gt;\n&lt;\/html&gt;<\/code><\/pre>\n<p>In this example, the attacker would attempt to get a user to load the malicious <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-43949-high-risk-sql-injection-vulnerability-in-mum-mapedit-web-application\/\"  data-wpil-monitor-id=\"39546\">web page in their vulnerable<\/a> browser. If successful, the malicious script within the iframe would execute in the top-level document&#8217;s context, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2023-34322-inadequate-precaution-in-xen-s-shadow-paging-leads-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"40985\">potentially leading<\/a> to a sandbox escape and further exploitation.<\/p>\n<p><strong>Mitigation<\/strong><\/p>\n<p>To mitigate this vulnerability, users are strongly advised to apply patches provided by the vendor. For <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-6436-critical-memory-safety-bugs-in-firefox-and-thunderbird-potentially-allowing-arbitrary-code-execution\/\"  data-wpil-monitor-id=\"64764\">Firefox and Thunderbird<\/a>, this means upgrading to versions 138 and 128.10 respectively. In the absence of the ability to upgrade, the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) could serve as a temporary mitigation measure. However, patching the affected software is the recommended and most effective <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-43971-critical-vulnerability-in-gobgp-paving-the-way-for-system-compromise\/\"  data-wpil-monitor-id=\"40122\">way to resolve the vulnerability<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The vulnerability identified as CVE-2025-4083 is a severe process isolation flaw that affects popular web browser Firefox and email client Thunderbird. This vulnerability is due to the improper handling of javascript: URIs, which could potentially allow malicious content to execute in the top-level document&#8217;s process instead of the intended frame. This could enable a [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"footnotes":""},"categories":[1],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-34697","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34697","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/comments?post=34697"}],"version-history":[{"count":11,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34697\/revisions"}],"predecessor-version":[{"id":58229,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34697\/revisions\/58229"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=34697"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=34697"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=34697"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=34697"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=34697"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=34697"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=34697"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=34697"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=34697"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}